Exposure, the best-validated treatment for panic disorder complicated by agoraphobia (PDA) and for obsessive-compulsive disorder (OCD, for whom response prevention is added) leads to good improvement in 60-75% of patients who complete treatment. However, residual disability generally remains, and these figures ignore the problems of treatment refusal, drop-out, and relapse. Attempts to explain the highly variable outcome and to improve upon these rates of change have yielded few cross- validated findings. Given the marked disability associated with these disorders and the concomitant public health costs, it is important to understand better why some patients drop-out, fail to benefit, or relapse. Identifying predictors of treatment success should help in the design of more effective treatment. In the proposed study, the investigators will complete the 6-month to 2-year follow-up data collection and analysis of data from 105 patients with PDA or OCD entering exposure-based treatment (with response prevention for OCD) during years 1-5 of this study. The effects of two major classes of predictors will be examined: Comorbidity and Expressed Emotion (EE). Defined as relatives' criticism of, and/or emotional over-involvement with the patient, EE has consistently predicted relapse at follow-up for schizophrenic and depressed patients treated as inpatients. In this study, the effects of EE on drop-out, immediate outcome, and relapse of outpatients with PDA and OCD are examined, and the construct of EE is explored to achieve a better understanding of its validity and meaning. EE and related measures were assessed via multiple methods: self-report, patients' report, videotaped relative-patient interactions, and the widely used Camberwell Family Interview administered to relatives. Treatment outcome was assessed with self-report, interview, and behavioral measures. Preliminary data analyses of this sample indicate that the patients' perceptions of their relatives' criticism may be an important predictor of poor outcome at follow-up, and that relatives who are poor problem-solvers may become critical when frustrated by the patients' behavior. Research on the effects of comorbid conditions on treatment is scant, but suggests that comorbid depression, generalized anxiety, and anxious personality disorders predict poor posttreatment outcome for PDA patients. Preliminary data from this sample suggest that comorbidity predicts poor outcome for both patient groups These data have important treatment implications and will be pursued Into follow-up in this application. Findings that comorbidity and EE are associated with poor outcome for patients with these severe anxiety disorders would have clear implications for development of adjunctive treatments to boost treatment response and maintenance of gains in these groups. Completion of the follow-up data collection is required for clear findings.